Illuminated sign



March 9, 1937. M. KNOBEL ILLUMINATED SIGN" Filed Jan. 14, 1936 ATTORNEYS Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE ILLUMINATED SIGN Islands Application January 14, 1936, Serial No. 59,020

3 Claims.

This invention relates to improvements in illuminated signs of the type disclosed in the patent to John Gordon Best, No. 2,014,271, of September 10, 1935. In this patent is disclosed an arrange- 5 ment for obtaining an optical illusion of movement or animation in stationary portions of a sign or the like by coloring the background and indicia portions of the sign with colors, the distinguishing hues of which are contrasting, mu-

tually exclusive and preferably complementary, and alternately illuminating the sign with light of the same colors in such rapid sequence that persistence of vision is effective to the extent that retinal impressions of the colors of the indicia and background portions, as illuminated by light of corresponding color, are retained until the next recurring illumination of the sign with light of that color so that the indicia and background portions each appears continuously in its own color irrespective of the color of light to which it is exposed. When the colors of light are alternated at proper frequency, that is, in the range from two to twenty per second, the indicia portion appears to be animated and to make the natural movements of the objects represented thereby.

The ordinary type of high power incandescent lamp is unsatisfactory as a source of light for this purpose due to the fact that there is too great a lag between the initiation of current flow and full filament incandescence. Low power incandescent lamps are suitable for use insofar as the extent of lag is concerned, but are unsatisfactory from the point of intensity of illumination.

An object of this invention is a high power incandescent lamp having sufficiently short lag between initiation of current fiow and full filament incandescence to render it suitable for use as the light source for illuminating the type of sign above described.

Other objects, novel features and advantages of this invention will become apparent from the following specification and accompanying drawing, wherein:

Fig. l is a diagrammatic elevation of an apparatus embodying the invention, and

Fig. 2 is an enlarged wiring diagram showing the incandescent lamps in horizontal crosssection.

A sign it) is composed of opaque or translucent material according to winch side it is intended to be viewed from and on the sign is painted, printed or otherwise aifixed a background portion II and an indicia portion l2, The indicia may consist of letters, characters, figures, arbitrary designs, pictorial representations or parts thereof and the background constitutes that portion of the sign immediately adjacent to the indicia extending out therefrom for an indeterminate distance. The background portion H and the indicia portion ii are of different colors, each of which is deficient in the predominating or distinguishing hue of the other. In the present instance, the background portion II is 001- ored green and the indicia portion I2 is colored red.

Illumination of the sign is accomplished by means of two electric incandescent lamps I3 and M respectively, each of which is provided with a suitable reflector I5. The lamp I3 is supplied with a light filter or screen l6 which permits green rays to pass while intercepting or excluding red rays and the lamp i4 is provided with a light filter or screen I! which permits red rays to pass while intercepting or excluding green rays. The filament of each of the incandescent lamps consists of two coils l8 and I9 lying in the same plane and defining a circle. The coils I8 and i9 are supported at one end by a lead wire 20 and at the other end by a lead wire 2|, both of which are sealed in the press or stem of the lamp in the usual manner. The coils l8 and H! are thus connected in parallel and are constructed so as to give the same amount of illumination but to have a much smaller lag between initial current fiow and full incandescence than, a single coil of equivalent voltage.

Energizing current is fed to the incandescent lamps I3 and M from a suitable supply line 22 through a circuit including the interrupter 23 rotated at constant speed by the motor 24. The construction of the interrupter is such that during half of its revolution current flows through one lamp and during the other half of. such revolution, current flows through the other lamp.

Fig. 2 illustrates one form of interrupter suitable for the purpose, but it is to be understood that this invention contemplates the use of any form of interrupter which will accomplish the desired result. The interrupter consists essentially of a rotatable member, on the periphery of which is provided a metal annulus 25 which is cut away for about half its Width over an arc of the cut-out portion being filled in with suitable insulation 26. A brush 21 is connected to one side of the line 22 while brushes 28 and 29 are connected through the lamps l3 and I4 respectively with the opposite side of the line 22. With this arrangement, current is caused to flow through the lamp 13 during one half revolution of the interrupter and through the lamp l4 during the other half revolution of said interrupter. The sign is thus alternately illuminated with green and red light.

By reason of the filament structure, the lag between the initial current flow and full filament incandescence is reduced to such extent that high power lamps are suitable for use at the frequency required for obtaining the desired illusion of movement, such frequency being from two to twenty cycles per second.

I claim:

1. A sign device comprising indicia and background portions of contrasting non-neutral col-' ors, the color of one of said portions being deficient in the distinguishing hue of the other portion which is deficient in the distinguishing hue of the first portion, means for alternately illumimating the sign with light of the same color as the indicia portion and light of the same color as the background portion, said means being operative at a frequency within the range defined on the one hand by the frequency at which a continuously retained retinal impression begins with respect to said colors and on the other hand by the frequency at which persistence of vision becomes wholly effective and comprising a pair of incandescent electric lamps, each lamp having its filament composed of sections connected in parallel whereby the lag between initial current flow and full incandescence of, said filament is unobjectionable at the operating frequency of the lamp and means for alternately energizing said lamps at the desired frequency.

2. A sign device according to claim 1 in which said filament sections are semi-circular and are arranged in the same plane to define a circular light source.

3. A sign device according to claim 1 in which the frequency of energization of said lamps lies in the range of two to twenty cycles per second MAX KNOBEL. 

